People will lose weight when they slim down with a friend.

人们若和朋友一起减肥，就会减轻体重。

《柯林斯英汉双解大词典》

So you have lost weight when you accelerate downwards.

总之，向下加速,则重量减小。

youdao

Of course, people put on weight when they consume more calories than they burn off.

当然，当人们摄入的能到超过他们消耗的能量时，体重就会增加。

youdao

People with heart failure tend to gain weight because fluids build up when the heart can't pump enough blood.

VOA: standard.2010.06.04

Let me ask another question, if you give this-- and we'll talk about this in a later lecture, but if you give this diet to laboratory animal-- rats, mice, whatever-- it's very common for animals to gain a good bit of weight when given access to this diet.

我们来看另一个问题,如果你给,我们将在以后的课上讨论这个话题,但如果你给实验室动物,像小白鼠之类的,给予某种类型的饮食,这种饮食习惯会使得体重增加

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

This normal weight animal like this has its whole equilibrium thrown off, its homeostasis thrown off when its dietary conditions change.

在饮食条件发生变化时,这些正常体重动物的生理平衡被打破,于是摈弃了原来的平衡饮食

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Mice from all three groups lost weight when they exercised, and their cholesterol levels lowered.

BBC: Exercise is good for health

Recent studies have suggested that up to 40% of people are under-weight when they're admitted to hospital.

BBC: NEWS | Health | 'I tried not to think about food'

The elderly and people of Asian descent are more likely to be at normal weight when diagnosed, for example.

CNN: Obesity paradox: Why being thin with diabetes is dangerous